return parentMutationGuard.withMutationDisabled(super.withMutationDisabled(action));
    }

    @Override
    protected boolean hasWithName(String name) {
        return (project.getModelRegistry() != null && project.getModelRegistry().state(ModelPath.path("tasks." + name)) != null) || super.hasWithName(name);
    }

    @Override
    public NamedDomainObjectCollectionSchema getCollectionSchema() {

    public boolean addAll(int index, Collection<? extends T> c) {
        assertMutable("addAll(int, Collection)");
        boolean changed = false;
        int current = index;
        for (T t : c) {
            if (!hasWithName(getNamer().determineName(t))) {
                getStore().add(current, t);
                didAdd(t);
                getEventRegister().fireObjectAdded(t);
                changed = true;
                current++;

                }
            }
        } else if (hasWithName(name)) {
            failOnDuplicateTask(name);
        }

        addInternal(task);
    }

    private static void failOnDuplicateTask(String task) {

        // do nothing
    }

    /**
     * Asserts that an item with the given name can be added to this collection.
     */
    protected void assertCanAdd(String name) {
        if (hasWithName(name)) {
            throw new InvalidUserDataException(String.format("Cannot add a %s with name '%s' as a %s with that name already exists.", getTypeDisplayName(), name, getTypeDisplayName()));
        }
    }